Cover picture for the Journal of Animal Ecology July Issue

Cover image: A Sociable weaver Philetairus socius colony. These large haystack-type structures are used by many different species, creating local biodiversity hotspots throughout the weaver's range. For certain taxonomic groups (terrestrial invertebrates and birds) these colonies are able to maintain this diversity, even as environmental harshness increases. This supports predictions from the stress gradient hypothesis, which states that the importance of positive interactions increases in harsher and more stressful environments.